<?php
require '../vendor/autoload.php';

function main()
{
    echo 'Please enter the radius which circle you want to calculate the area of: ';
    if ($r = fgets(STDIN)) {
        $r = (float)rtrim($r);

        disp('The area of the circle with radius in ' . $r . ' is ' . M_PI * pow($r, 2) . '.');
    }
}

main();
